Standardized orthodontic tooth-positioning and retaining device



Nov.18,-1969 D.J.SHiI 'L IDAY 3,478,429

STANDARDIZED ORTHODONTIC TOOTH-POSITIONING AND RETAINING DEVICE FiledMay 21, 1968 2 Sheets-Sheet 1 INVENTOK DOUGLAS J. SHILLIDAY BY MAHONEY,MIL R 8 RAMBO BYW ' A TTORNEYS Nov. 18, 1969 I D. J. SHILLIDAY 3,478,429

STANDARDIZED ORTHODONTIC TOOTH-POSITIONING AND RETAINING DEVICE FiledMay 21, 1968 2 Sheets-Sheet 2 INVENTOR. DOUGLAS J. SHILLIDAY BY MAHQNEY,MILLER 8 RAMBO A TORNEYS United States Patent O1 fice 3,478,429 PatentedNov. 18, 1969 3,478,429 STANDARDIZED ORTHODONTIC TOOTH-POSI- TIONING ANDRETAINING DEVICE Douglas J. Shilliday, Upper Arlington, Ohio (1501London Drive, Columbus, Ohio 43221) Filed May 21, 1968, Ser. No. 730,716Int. Cl. A61c 7/00 U.S. Cl. 3214 4 Claims ABSTRACT OF THE DISCLOSUREBACKGROUND OF THE INVENTION This invention relates generally toorthodontic appliances, and more specifically to a standardized,preformed, tooth-positioning and retaining device intended to be worn ona periodic basis by persons whose teeth have been previously subjectedto correction by means of metal bands, arch wires, and the like.

Following correction of teeth by means of the usual metal bands, archwires, etc., it has been found desirable to provide orthodontic patientswith what is commonly referred to as a retainer. One type of retainer ingeneral use comprises a custom-molded, rubber-like mouthpiece which ismade from cast impressions of the patients teeth in their correctedpositions. These retainers are usually worn by the patient at periodicintervals of privacy, such as while sleeping, for the purpose of holdingand supporting the somewhat mobile teeth in their desired, finallycorrected positions until the teeth have become stabilized. Typicalexamples of such retainers are described in prior U.S. patents toKesling Nos. 2,467,432 and 2,531,222. Still another type of retainerutilizes a rigid, substantially inflexible, plastic body which iscustommolded to correspond to the individuals corrected dentures.

These prior art retainers have been subject to numerous objections bothby the patient, as will as by the orthodontist. First, custom-moldedretainers are relatively expensive due to the time and skills requiredin their manufacture. Secondly, such retainers are usually fabricated bya remotely located manufacturer from plaster casts supplied by theorthodontist, and this results in a serious delay in supplying thepatient with the needed support. Further, these retainers usually coverand encase the entire dental arch and are, therefore, rather bulky anduncomfortable to the patient.

Heretofore, it was believed necessary to custom-mold these retainers niorder to faithfully reproduce therein actual impressions correspondingto the corrected teeth of each individual patient. This belief stemmedfrom the fact that tooth width, arch length and other dimensions ofcorrected dental arches vary with the individual person.

However, I have found through clinical tests and measurements of some700 different patients that while there were dimensional differences intooth width, arch length and intercuspid width (chordal distance) of theupper and lower six anterior teeth of different patients, there was verylittle, if any, difference in the curvature of the corrected dentalarches in approximately 95% of the patients observed. In other words, inthe greater majority of corrected dental arches, the straight linechordal distance between the cuspids of the maxillary arch and betweenthe cuspids of the mandibular arch increases in direct proportion to thecircumferential lengths of these arches.

SUMMARY AND OBJECTS OF INVENTION The present invention provides atooth-positioning and retaining device in the form of anon-custom-molded, resiliently flexible, mouthpiece body which isdimensionally standardized so as to accommodate and afford the desiredstabilizing support to the upper and lower six anterior teeth of thegreater majority of corrected dental arches.

It is the primary object of this invention to provide a comparativelyinexpensive standardized tooth-positioner and retainer which may bestocked by the average orthodontist and fitted to the average correctedpatient with ease and facility, and without requiring preparation of theusual impressions, plaster casts, etc. heretofore necessary in theproduction of custom-molded positioners and retainers.

Another object is to provide a standardized tooth-positioner in the formof a resiliently flexible plastic mouthpiece which is formed with upperand lower generally arcuate troughs or grooves defined by limited areasurfaces which will aflord the desired stabilizing support to thelabial, lingual and incisal surfaces of the upper and lower six anteriorteeth of a patient wearing the positioner, and which may be quickly andeasily fitted to the individual patient simply by trimming off thedistal edge portions of the mouthpiece to make its arcuate lengthconform to the arcuate length of the patients dental arch, measured fromdistal edge to distal edge of the cuspids.

For a further and more detailed understanding of the present inventionand the various objects and advantages thereof, reference is made to thefollowing detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a frontal perspective view ofthe tooth-positioning and retaining device of this invention showing thesame in operative position covering the upper and lower six anteriorteeth of the dental arches which are shown in broken lines;

FIG. 2 is a perspective view of the retaining device looking toward therearward or lingual side thereof;

FIG. 3 is an enlarged, vertical sectional view taken through the centralaxis of the retaining device, as indicated by the line 3-3 of FIG. 2;

FIG. 4 is a horizontal sectional -view taken along the line 44 of FIG. 3and showing the present retaining device in association with the upperor maxillary dental arch, the latter being shown in broken lines;

FIG. 5 is a similar view taken along the line 5-5 of FIG. 3 and showingthe relationship of the retaining device to the lower or mandibulardental arch;

FIG. 6 is a horizontal sectional view taken along the line 6-6 of FIG. 3and looking into the upper trough of the retaining device;

FIG. 7 is a horizontal sectional view taken along the line 77 of FIG. 3looking into the lower trough of the retaining device;

FIG. 8 is a detailed vertical sectional view taken along the line 88 ofFIG. 6;

FIG. 9 is a diagrammatic sectional view showing the relative locationand dimensions of the lateral incisor-engaging ribs which are associatedwith the upper trough of the retainer; and

FIG. 10 is a similar view showing the relative location and dimensionsof the incisor-engaging rib of the lower trough of the retainer.

3 DETAILED DESCRIPTION By reference to the drawings, it will be notedthat the present tooth-positioning and retaining device takes the formof an integral, generally arcuate mouthpiece-like body generallyindicated by the reference numeral 10. In accordance with thisinvention, the body is molded or otherwise formed with a standardizedshape and With standardized dimensions so that it may be used bysubstantially any person who has undergone orthodontic correction andwhose dental arches present six normal upper and lower front teeth. Thebody 10 is formed from a rubber-like, resiliently flexible, non-toxicmaterial, such as natural rubber, or a silicone rubber elastomer whichis non-irritating and compatible with the tissues of the mouth.

The body 10 includes a forward, labial flange portion 11, a rearward,lingual pad portion 12, and an intermediate incisal web, ledge or shelf13 which interconnects the labial flange and lingual pad portions of thebody. The labial flange portion 11 his a substantially smooth, generallyconvex front wall surface 14 and a substantially smooth, generallyconcave rear wall surface 15. The labial flange portion 11 is intendedto fit between the anterior teeth and the lips of the wearer, and has aheight to extend well over the gingival tissues of both the maxillaryand mandibular arches when the anterior teeth are closed upon theincisal shelf 13 of the body.

The lingual pad portion 12 of the body is formed with a generally convexforward wall surface 16 disposed in rearwardly spaced, opposed relationto the concave wall surface of the labial flange portion. The Wallsurfaces 15 and 16 define with the interconnecting incisal shelf portion13 a pair of upwardly and downwardly opening grooves or troughs 17 and18, respectively. The troughs 17 and 18 are generally arcuate and taperinwardly toward the incisal shelf portion 13 of the body. While thecontour of the walls 15 and 16 follows the general contour of the upperand lower dental arches of the average human mouth in the region of thesix anterior teeth, it will be noted that these wall surfaces areentirely devoid and free of individual tooth-like impressions such as tocharacterize the ordinary types of custom-molded retainers. In thisregard, I have found that so long as a tooth is contacted withsubstantially equal force on its opposite labial and lingual surfacesand on its incisal surface, the tooth will be stabilized and preventedfrom movement, regardless of whether the force is distributed over theentire area thereof, or applied to a relative small and limited area ofthe tooth surface. By the same token, a slightly misaligned tooth may beurrged to a desired finally corrected position by the application ofmore force in one direction than another, even though the force beapplied to a limited area of the tooth.

Accordingly, rather than forming the walls of the troughs 17 and 18 withindividual tooth-like impressions to match the dentures of oneparticular person, I form the walls of the troughs 17 and 18 withrelatively offset areas arranged in a predetermined pattern so as toprovide stabilizing and/or corrective forces to the anterior teeth ofpractically any person having corrected dental arches and having sixnormal, upper and lower anterior teeth. Toward this end, the concavewall 15 of the upper or maxillary trough 17 is formed with a pair ofrelatively spaced, generally vertically arranged ridges, ribs orprotuberances 19 which project into the trough 17 in position to contactthe labial surfaces of the upper lateral incisors 20 of the wearer. Aswill be noted particularly in FIGS. 6 and 8, the ribs 19 are formed withhorizontal continuations 19a which extend across and project upwardlyfrom the bottom of the trough 17 for contact with the incisal surfacesof the upper lateral incisors 20. By the same token, the concave wall 15of the lower or mandibular trough 18 is formed with a relatively wider,generally vertically arranged ridge-like protuberance 21 which extendsinto the trough to engage the labial surfaces of the four lower centraland lateral incisors 22 and 23 of the wearer.

As previously indicated, tests and measurements made on approximately700 different persons having corrected dental arches showed thefollowing significant facts:

(1) The upper lateral incisors in each case were approximately 1 mm.shorter and 1 mm. thinner labio-lingually than the upper centralincisors;

(2) The upper cuspids in each case were approximately 1 mm. longer and 1mm. thicker labio-lingually than the upper central incisors;

(3) The lower six anterior teeth in each case were approximately thesame length, but the lower cuspids were approximately 1 mm. thickerlabio-lingually than the lower central and lateral incisors;

(4) The total arch length of the six upper anterior teeth in thesmallest case was 38 mm. compared with a total arch length of 54 mm. forthe corresponding teeth of the largest case;

(5) The straight line distance between the points of the upper cuspidsin the smallest case was 30 mm. and in the largest case 40 mm.

(6) The widest upper central incisor encountered measured 10.5 mm. inwidth;

(7) In the narrowest case, the combined width of two upper central andlateral incisors was 13 mm;

(8) The combined width of the two lower central inisors was 12 mm. inthe widest case; and

(9) The combined width of the four lower central and lateral incisorswas 18 mm. in the narrowest case found.

Utilizing these statistics, I have found that the ribs 19 and theirextensions 19a should project outwardly from the wall 15 and upwardlyfrom the bottom of the trough 17, respectively, a distance of 1 mm. toconform to the normal, dimensional oifset of the upper lateral incisorsrelative to the central incisors. Also, the relatively thickened ridgeor protuberance 21 of the lower trough 18 should project outwardly fromthe concave wall 15 a distance of 1 mm. to conform to the normal insetrelationships of the four lower central and lateral incisors relative tothe lower cuspids. I have also found that in order to prevent overlap orcontact of the ribs 19-19a with the upper central incisors in themaximum tooth width cases, or contact with the upper cuspids in theminimum width cases, the inner edges of the ribs 19- 19a must be located10.5 mm. outwardly on each side of the central axis A of the retainerbody, or a total arcuate distance of 21 mm. apart from one another, andmust not be over 2.5 mm. wide. By the same token, the ridge orprotuberance 21 of the lower trough must not extend beyond 9 mm. oneither side of the central axis A, or, stated another way, must not beover 18 mm. in arcuate length, otherwise, the ridge 21 would encroachupon the lower cuspids of the minimum width cases. These criticaldimensions are shown in the diagrams of FIGS. 9 and 10, and should beclosely adhered to in the manufacture of the present tooth-positioningand retaining device in order for it to be usable in the maximum numberof cases.

Thus, to summarize, the upper or maxillary trough 17 of the body 10 ischaracterized by a central incisorreceiving region located between theribs 19-19a and having an arcuate length of 21 mm., lateralincisor-receiving regions located adjacent the ribs 19-1951, each ofwhich is 2.5 mm. in width, and cuspid-receiving regions locatedoutwardly from the ribs 1919a. As will be noted from FIGS. 4 and 9, thecuspid-receiving regions of the trough 17 are approximately 1 mm. widerthan the central incisor-receiving region and approximately 2 mm. widerthan the lateral incisor-receiving regions. Also, the bottom surface ofthe upper trough 17 in its cuspidreceiving regions is approximately 1mm. lower than in the central incisor-receiving region and 2 min. lowerthan the rib extensions 1%, as indicated in FIG. 8. The lower ormandibular trough 18 is characterized by a substantially uniform depthat the incisal shelf 13, but the trough 18 is approximately 1 mm. widerin its cuspid-receiving regions than in its central and lateralincisor-receiving region.

The present tooth positioning and retaining device is preferablymanufactured and sold with a labial arch length of 54 mm. so as to spanand encase the upper and lower six anterior teeth of the largest dentalarch observed by me to date. Thus, when the orthodontist encounters apatient with an anterior arch (cuspid to cuspid) which is less than 54mm. the distal end portions of the retainer body may be cut or trimmedoff so that the ends of the labial flange will just cover the distaledges of the cuspids without encroaching upon the 'bicuspids.

It will thus be seen that the present invention provides a standardized,non-custom-molded, tooth-positioner or retainer which may be stocked inquantities by the orthodontist and quickly fitted to the great majorityof his patients simply by cutting the distal edges of the labial flangeand incisal shelf portions of the device so that its arch length willmatch the arch length of the six anterior teeth of the particularpatient. If desired, the lingual pad portion of the device may be formedat its opposite sides with posterior extensions which project rearwardlyalong the lingual surfaces of the posterior teeth to provide additionalstabilizing surfaces for the device.

Having thus described this invention, what is claimed 1. A standardizedtooth-positioning and retaining device to be worn by orthodonticallycorrected persons having upper and lower six anterior teeth, ranging inwidths from predetermined minimum to predetermined maximum widths, saiddevice comprising a one-piece, resiliently flexible, mouthpiece bodyhaving a central axis and including a generally arcuate labial flangeportion, a lingual pad portion extending rearwardly from said labialflange portion, and an incisal shelf portion connecting said labialflange portion with said lingual pad portion, the labial flange andlingual pad portions of said body being formed, respectively, withrelatively opposing concave and convex wall surfaces converging towardthe incisal shelf portion of said body and defining therewith upwardlyand downwardly opening, generally arcuate troughs to receive the upperand lower six anterior teeth of an orthondontically corrected person,

the concave and convex wall surfaces of said troughs being devoid ofindividual tooth-like impressions, but the concave wall of the labialflange portion of said body being formed with protuberances projectinglingually into said troughs and arranged, upon closure of said anteriorteeth on the incisal shelf portion of said body, to engage at leastlimited areas on the labial surfaces of the upper and lower lateralincisors without touching the adjacent cuspids, regardless of variationsin tooth widths between said predetermined minimum and maximum widths.

2. A standardized tooth-positioning and retaining device according toclaim 1, wherein the incisal shelf portion of said body is formed with apair of ribs projecting upwardly into the upwardly opening trough ofsaid body, said ribs being spaced from one another equidistantly on eachside of the central axis of said 'body and being arranged upon closureof said teeth on said incisal shelf portion, to engage a limited area onthe incisal surface of each of the upper lateral incisors only,regardless of variations in tooth widths between said predeterminedminimum and maximum widths.

3. A standardized tooth-positioning and retaining device according toclaim 1, wherein the protuberance formed on the concave wall of thelabial flange and projecting within the downwardly opening trough ofsaid body comprises a continuous ridge arranged to completely span thelower central incisors and at least a part of each of the lower lateralincisors upon closure of said teeth upon the incisal shelf portion ofsaid body.

4. A standardized tooth-positioning an retaining device according toclaim 2, wherein the protuberances formed on the concave wall of thelabial flange and projecting within the upwardly opening trough of saidbody comprise a pair of relatively spaced apart, vertical ribs locatedcontiguous to and in common vertical planes with the ribs formed on theincisal shelf portion of said body;

References Cited UNITED STATES PATENTS 2,775,036 12/1956 Kesling 32143,319,626 5/1967 Lindsay 3214 FOREIGN PATENTS 67,616 10/1957 France.

ROBERT PESHOCK, Primary Examiner

